Apparatus for generating pneumatic pressure pulses for application to the external acoustic meatus of a patient

ABSTRACT

An apparatus for producing pressure pulses intended for application to the external acoustic meatus of a patient, for the purpose of influencing the hydrodynamic system of the inner ear in the treatment of certain diseases, particularly Menieres disease, comprises two rotary air-pumps (1, 2) of variable, controllable speed. Respective pressure sides of the two pumps (1, 2) can be selectively connected to and disconnected from a common pressure-pulse output line (7), by means of a respective controllable valve (5, 6). The pumps are driven by electric motors (3, 4) and the rotational speed of the motors and the settings of the electrically operable valves (5, 6) are controlled by a control unit (9) incorporating a microprocessor, in response to a program relating to a desired shape, frequency, amplitude, duration etc. of the generated pressure pulses, this program being stored in the control unit. The apparatus also includes a pressure transducer (8) which is connected to the output line (7) and which produces a signal representing the momentary pressure prevailing in the output line (7), this signal being applied to the control unit and used therein to control the two pumps (1, 2) and the two valves (5, 6).

The present invention relates to an apparatus for generating pneumaticpressure pulses for application to the external acoustic meatus, the earopening, of a patient in order to influence the hydrodynamic system ofthe inner ear.

It has been possible to establish that changes in the hydrodynamicsystem of the inner ear, including the endolymph and perilymph, affectthe function of the ear and can be thought to be the cause of variousdisease conditions. One such disease is Menieres disease, the symptomsof which are extremely troublesome to the patient, such as disturbedbalance, vertigo, impaired hearing, singing noises in the ear, tinnitus,etc.. Medical tests have shown that these symptoms can be easedconsiderably, and in many cases completely cured, by means of a courseof treatment in which pneumatic pressure pulses are applied to theexternal acoustic meatus of the patient, these pressure pulsespropagating through the middle ear to the inner ear and thereinfluencing the hydrodynamic system of the said inner ear. Propagationof the pressure pulses from the external acoustic meatus to the innerear can be facilitated by implanting in the patient a transmyringialtube, made for example of Teflon®. Those tests which have been carriedout with this form of treatment have shown that in order to obtain thebest results, it must be possible to vary and to determine precisely,inter alia, the shape, frequency and amplitude of these pulses inrespect of each individual patient.

For the purpose of generating the pressure pulses necessary in this formof treatment there has earlier been proposed, and used, apparatus whichinclude one or more membrane pumps, pressure reservoirs, mechanicallyadjustable throttle devices, etc., such as described in theInternational Patent Application No. PCT/SE83/00013, Publication NumberWO 83/02556. Great difficulties have been experienced, however, inproducing with sufficient accuracy pressure pulses which have theparticular parameters necessary for each individual patient, e.g. suchparameters as pulse shape, frequency and amplitude, by means of theseearlier proposed and used apparatus. A prime difficulty in this respectis one of avoiding the temporary occurrence of underpressure in theexternal acoustic meatus, such underpressures being undesirable.

Accordingly, the object of the present invention is to provide a noveland improved apparatus for generating the pneumatic pressure pulsesdesired in the form of treatment aforedescribed in which thosepressure-pulse parameters of interest can be readily varied anddetermined with a high degree of accuracy, stability and reliability.

The characterizing features of the apparatus according to the inventionare set-forth in the following claims.

The invention will now be described in more detail with reference to theaccompanying drawing, in which

FIG. 1 is a diagram illustrating a typical shape of the pressure pulsesto be produced by the apparatus according to the invention;

FIG. 2 is a simplified pneumatic-electric block diagram of oneembodiment of apparatus according to the invention;

FIG. 3 illustrates an exemplifying embodiment of a proposed, conceivableexternal configuration of an apparatus according to the invention; and

FIG. 4 illustrates an exemplifying embodiment of an apparatus accordingto the invention temporarily connected to a separate programming unit.

The diagram in FIG. 1 exemplifies a typical shape of the pressure pulsesto be produced by the apparatus according to the invention. Thetreatment cycle consists of a plurality of mutually sequential pressurepulses P, having a substantially sinusoidal modulation. Those parametersof interest when effecting treatment are:

the pulse base pressure B_(p),

the maximum pulse pressure P_(p),

the pulse modulation frequency F_(m),

the individual pulse length T_(p), and

the pulse time-spacing T_(i)

The total number of pulses P in each pulse series is also of interest,as is optionally also the number of such pulse series when a pluralityof pulse series is applied to the patient during the course of a singletreatment period, and therewith the time lapse from the end of one pulseseries to the beginning of the next.

In order to achieve the best possible results from the treatmentadministered, it shall be possible to vary all of these pressure-pulseparameters in a ready and simple manner, and to set the parameters todesired values with a high degree of accuracy and reliability independence on the needs of each individual patient. It shall be noted inthis respect that the parameters B_(p), P_(p), T_(p), T_(i) and F_(m)need not necessarily be the same for all pulses in a pulse series. Inaddition, it is preferred that no underpressure occurs, for example atthe end of each pulse. Examples of suitable setting ranges forindividual parameters are:

B_(p) =0-30 mb

P_(p) =0-30 mb

T_(p) =0.1-60 s

T_(i) =0-60 s

F_(m) =0-20 Hz

The total length of a pulse series can be set for times of up to 10minutes. The time spacing between mutually sequential pulse series, whenapplying a number of such series, can also be set to values of up to 10minutes.

As illustrated by way of example in FIG. 2, the pressure-pulsegenerating apparatus according to the invention comprises two rotary airpumps 1 and 2 which are driven continuously at variable, controllablespeeds by means of a respective electric motor 3 and 4. The pumps 1,2may be sliding-vane type pumps, and the pumps with associated drivemotors may, for example, be of the kind retailed under the name Microvac3 by the Company Edwards, England. Each of the pressure sides of the twopumps is connected to a respective electrically controllable, 3-way,2-position micro-valve 5 and 6. The micro-valves may, for example, be ofthe type LFAA 1200118H from the Lee Company, Connecticut, USA. Each ofthe pumps 1,2 can be connected to a common output hose or line 7 bymeans of the microvalves 5,6, or so that this connection can be broken.When one of the valves 5,6 breaks the connection between the associatedpump 1 or 2 and the output hose, this valve simultaneously places thehose 7 in communication with ambient atmosphere. The output hose 7, inwhich the pressure pulses generated by the apparatus occur, is connectedat its distal end to a suitably designed ear plug 11, which can beinserted into the external acoustic meatus of a patient, so as toconnect the hose 7 thereto in a pressure-tight manner. The ear plug 11may advantageously be provided with an inflatable cuff 12, for sealingengagement with the walls of the external acoustic meatus. The pressurerequired to seal the cuff 12 against said walls may suitably be takenfrom the pressure side of pump 2. The apparatus also includes a pressuretransducer 8, which is connected to the output hose or like line 7 andwhich produces an electric signal representing the momentary pressure inthe hose 7. The pressure transducer 8 may, for example, comprise amicro-pressure-transducer of the type KPY32R from Siemens AG.

The apparatus also incorporates a control unit 9, which is arranged toreceive the pressure signal produced by the transducer 8 and whichcontrols the pump drive motors 3,4 and the settings of respective valves5 and 6. The control unit 9 includes a microprocessor which is suitablyconstructed for the aforesaid purpose and which operates in response toa program inserted and stored therein, this program containing allrelevant data regarding the aforesaid parameters for the series ofpressure pulses encompassed by the treatment intended for administrationto a particular patient.

The pulse base pressure B_(p) is determined by means of one of theaforesaid pumps, for example the pump 1, steering of the valve 5connected to this pump determining the pulse length T_(p) and the timespacing T_(i) between mutually sequential pulses. The rotational speedof the second pump 2 will therewith determine the maximum pulse pressureP_(p), whereas steering of the valve 6 connected to the other pump 2will determine the modulation frequency F_(m). It has been found thatwhen using an apparatus of this construction the desired series ofpressure pulses having parameters which are suitable for each individualpatient can be produced to an extremely high degre of precision andstability. Because the valves 5,6 place the hose 7 in communication withambient atmosphere when breaking the connections of the associated pumps1,2 to the output hose 7, it is ensured, in a highly effective manner,that no deleterious pressure build-up will occur in the externalacoustic meatus of the patient. The apparatus according to the inventionalso affords approximative sinusoidal modulation of the pressure pulsesin a desirable manner, and totally avoids the occurrence of temporaryunderpressure in the hose 7.

An apparatus according to the invention can readily be given smalldimensions, of the same order of magnitude as a conventional personalcalling device, thereby enabling the patient to carry the device onhis/her person and to administer treatment to himself/herself when foundnecessary.

An apparatus according to the invention may also be provided withnecessary auxiliary devices, for example a set of keys for entering apulse-generation control program into the apparatus, or changing anexisting program. The apparatus may also be provided with means forvisual display and/or write-out of the pulse-generation control programstored in the control unit. An apparatus provided with such programmingand display means is best suited for use in hospitals, medical treatmentclinics, and by doctors. A compact, readily carried apparatus intendedfor the patient's personal use, is, on the other hand, suitablyconstructed so that when necessary it can be connected to a separateprogramming unit which is provided with a keyboard for entering aprogram into and changing an existing program in the apparatus whentemporarily connected to the program unit, and which also incorporatesdisplay and/or write-out means for visual presentation of the programdata stored in the temporarily connected apparatus. FIG. 3 illustratesby way of example a conceivable external design of such a patientapparatus 10, whereas FIG. 4 illustrates an exemplifying embodiment ofone such personal apparatus 10 connected temporarily to a separateprogramming unit 13.

Such personal apparatus may also conceivably be constructed to enable itto be connected to any type of data terminal of standard design withrespect to the aforesaid programming procedure. Such connection may alsoconceivably be effected with the aid of suitable modem through thetelephone network.

An apparatus according to the invention which is intended to be usedsolely by one specific patient may also be constructed, to advantage, sothat in addition to containing requisite data concerning the treatmentprogram currently applicable to the patient, the apparatus control unitalso contains a complete record of all previous treatment programs usedin respect of the same patient, so that these previous programs can bevisually presented or written-out for study by the dootor concerned,through the agency of a programming unit 13. The memory incorporated inthe apparatus may also conveniently contain other pertinent dataconcerning the patient, so that the patient's doctor has ready access tosuch data.

It will be understood that an apparatus according to the invention maybe constructed differently to the apparatus aforedescribed. For example,the pumps, valves and pressure transducers used may be different tothose used in the described embodiment. In order to reduce thedimensions of the apparatus, two pumps combined to form an integral pumpunit may be used for example.

I claim:
 1. An apparatus for generating pneumatic pressure pulses forapplication to the external acoustic meatus of a patient for the purposeof influencing the hydrodynamic system of the inner ear, comprising:tworotary air-pumps (1,2) of variable controllable speed; two controllablevalves (5,6) downstream of said two rotary air-pumps, one said valvereceiving the output of one of said rotary air-pumps and another of saidvalves receiving the output of another of said air-pumps; an output line(7) from said valves and a meatus mating means (11) for pressure-tightconnecting with the external acoustic meatus of the ear of the patientalong said output line; and control means (9) for controlling the speedof the two air-pumps (1,2) and the settings of the two valves (5,6) toproduce a pulsed output of air to the output line (7), the meatus matingmeans (11) and the external acoustic meatus of the ear of the patientaccording to a preselected program controlling the shape, frequency andamplitude of the pressure pulses produced in the output line (7).
 2. Anapparatus according to claim 1 further comprising pneumatic means (12)to control said pressure-tight connection.
 3. An apparatus according toclaim 1, characterized in that the control unit is provided with, or isconnectable to means for reading said program into the control unit. 4.An apparatus according to claim 1, characterized in that the controlunit (9) is provided with, or is connectable to means for the visualpresentation and/or write-out of data relating to the program stored inthe control unit.
 5. An apparatus according to claim 1, characterized inthat said valves (5,6) are arranged to place the output line (7) incommunication with the ambient atmosphere when breaking said connectionbetween said output line (7) and the pressure side of the associatedpump means (1,2).
 6. An apparatus according to claim 5 characterized inthat the control unit is provided with, or is connectable to means forreading said program into the control unit.
 7. An apparatus according toclaim 1, characterized by a pressure transducer (8) which is connectedto said output line (7) and which is adapted to produce a signalrepresenting the momentary pressure prevailing in the output line, thissignal being applied to the control unit (9).
 8. An apparatus accordingto claim 7 characterized in that the control unit is provided with, oris connectable to means for reading said program into the control unit.9. An apparatus according to claim 7 characterized in that said valves(5,6) are arranged to place the output line (7) in communication withthe ambient atmosphere when breaking said connection between said outputline (7) and the pressure side of the associated pump means (1,2). 10.An apparatus according to claim 9 characterized in that the control unitis provided with, or is connectable to means for reading said programinto the control unit.